Well, this movement from a laptop to plugpbx had made for difficult troubleshooting because i had to sync versions on both systems to backup/restore, ie transfer my settings. So, its difficult to know which problem derives from plugpbx or the debian installation, or from upgrading Asterisk/FreePBX.
Last night i noticed my MWI message waiting indicator light was not working on any of my phones when a message came in. In the EXTENSIONS menu option, go down to DEVICE OPTIONS. One of the options is MAILBOX. Well, it used to work just fine if you had XXX@device xxx being the extension #. I found the problem when i deleted the extension and recreated it and then noticed the difference. Let me save you the time.
change your xxx@device to xxx@default
MWI will come back to life!
Hope i save someone some time.
iBoston
